ObjectMonitor.java revision 9883:903a2e023ffb 
1/*
2 * Copyright (c) 2001, 2014, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25package sun.jvm.hotspot.runtime;
26
27import java.util.*;
28
29import sun.jvm.hotspot.debugger.*;
30import sun.jvm.hotspot.oops.*;
31import sun.jvm.hotspot.types.*;
32
33public class ObjectMonitor extends VMObject {
34  static {
35    VM.registerVMInitializedObserver(new Observer() {
36        public void update(Observable o, Object data) {
37          initialize(VM.getVM().getTypeDataBase());
38        }
39      });
40  }
41
42  private static synchronized void initialize(TypeDataBase db) throws WrongTypeException {
43    heap = VM.getVM().getObjectHeap();
44    Type type  = db.lookupType("ObjectMonitor");
45    sun.jvm.hotspot.types.Field f = type.getField("_header");
46    headerFieldOffset = f.getOffset();
47    f = type.getField("_object");
48    objectFieldOffset = f.getOffset();
49    f = type.getField("_owner");
50    ownerFieldOffset = f.getOffset();
51    f = type.getField("FreeNext");
52    FreeNextFieldOffset = f.getOffset();
53    countField  = type.getJIntField("_count");
54    waitersField = type.getJIntField("_waiters");
55    recursionsField = type.getCIntegerField("_recursions");
56  }
57
58  public ObjectMonitor(Address addr) {
59    super(addr);
60  }
61
62  public Mark header() {
63    return new Mark(addr.addOffsetTo(headerFieldOffset));
64  }
65
66  // FIXME
67  //  void      set_header(markOop hdr);
68
69  // FIXME: must implement and delegate to platform-dependent implementation
70  //  public boolean isBusy();
71  public boolean isEntered(sun.jvm.hotspot.runtime.Thread current) {
72    Address o = owner();
73    if (current.threadObjectAddress().equals(o) ||
74        current.isLockOwned(o)) {
75      return true;
76    }
77    return false;
78  }
79
80  public Address owner() { return addr.getAddressAt(ownerFieldOffset); }
81  // FIXME
82  //  void      set_owner(void* owner);
83
84  public int    waiters() { return waitersField.getValue(addr); }
85
86  public Address freeNext() { return addr.getAddressAt(FreeNextFieldOffset); }
87  // FIXME
88  //  void      set_queue(void* owner);
89
90  public int count() { return countField.getValue(addr); }
91  // FIXME
92  //  void      set_count(int count);
93
94  public long recursions() { return recursionsField.getValue(addr); }
95
96  public OopHandle object() {
97    return addr.getOopHandleAt(objectFieldOffset);
98  }
99
100  // contentions is always equal to count
101  public int contentions() {
102      return count();
103  }
104
105  // FIXME
106  //  void*     object_addr();
107  //  void      set_object(void* obj);
108
109  // The following four either aren't expressed as typed fields in
110  // vmStructs.cpp because they aren't strongly typed in the VM, or
111  // would confuse the SA's type system.
112  private static ObjectHeap    heap;
113  private static long          headerFieldOffset;
114  private static long          objectFieldOffset;
115  private static long          ownerFieldOffset;
116  private static long          FreeNextFieldOffset;
117  private static JIntField     countField;
118  private static JIntField     waitersField;
119  private static CIntegerField recursionsField;
120  // FIXME: expose platform-dependent stuff
121}
122